TECHNICAL REPORT DOCUMENTATION PAGE motor vehicles in the Traffic Accident ...

110 Pages·2014·4.54 MB·English

by  Yuanyuan Zhang

ADA Notice
For individuals with sensory disabilities, this document is
STATE OF CALIFORNIA DEPARTMENT OF TRANSPORTATION
available in alternate formats. For information call (916) 654-

6410 or TDD [phone] or write Records and Forms
TECHNICAL REPORT DOCUMENTATION PAGE Management, 1120 N Street, MS-89, Sacramento, CA 95814.
TR0003 (REV. 10/98)
1. REPORT NUMBER 2. GOVERNMENT ASSOCIATION NUMBER 3. RECIPIENT’S CATALOG NUMBER
CA14-2302

4. TITLE AND SUBTITLE 5. REPORT DATE

Develop a Plan to Collect Pedestrian Infrastructure and Volume Data May 31, 2014
for Future Incorporation into Caltrans Accident Surveillance and 6. PERFORMING ORGANIZATION CODE

Analysis System Database

7. AUTHOR(S)
Yuanyuan Zhang, Frank R. Proulx, David R. Ragland, Robert J.
Schneider, and Offer Grembek,
9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. WORK UNIT NUMBER

UC Berkeley Safe Transportation Research & Education Center
2614 Dwight Way, #7374 11. CONTRACT OR GRANT NUMBER

Berkeley, CA 94720-7374
65N2302
12. SPONSORING AGENCY AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED

California Department of Transportation Final report, 6-2012 to 5-2014
Division of Research, Innovation and System Information, MS-83 14. SPONSORING AGENCY CODE

1227 O Street

Sacramento CA 95814
15. SUPPLEMENTAL NOTES

16. ABSTRACT
This project evaluates the feasibility of developing a pedestrian and bicycle infrastructure database and
volume database for the California state highway system. While Caltrans currently maintains such data for
motor vehicles in the Traffic Accident Surveillance and Analysis System - Transportation System
Network (TASAS-TSN) database, the agency does not keep records on pedestrian or bicycle facilities. This
information is crucial for improving the safety of these vulnerable road users. This project developed a
proposed database structure and corresponding data collection methodology. It is recommended that the
databases be linked to TASAS using the connection ID instead of incorporating them directly into the
existing database. The volume and infrastructure databases will be constructed separately to accommodate
different data collection procedures. In particular, volume data should be updated more regularly than
infrastructure data. Volume data must be collected during field visits either manually or using automated
collection methods, while infrastructure data can be collected remotely using mapping services or in the
field during field visits. The research team tested the structure and collection methodology by populating
the database for 100 miles of state highway across two districts. Parallel to testing the consistency and
integrity of the database, the team also generated a time-cost estimate for data collection for different
facilities across the state highway system. The research team estimates that collecting the data in the field
for the entire state highway system will require approximately 9,000 hours, while remote (computer-based)
data collection will require about 4,000 hours.
17. KEY WORDS 18. DISTRIBUTION STATEMENT
TASAS, Pedestrian Volume, Infrastructure, No restrictions. This document is available to the
database public through the National Technical Information
Service, Springfield, VA 22161
19. SECURITY CLASSIFICATION (of this report) 20. NUMBER OF PAGES 21. PRICE
(cid:20)(cid:20)(cid:19)
Unclassified N/A
Reproduction of completed page authorized
DISCLAIMER STATEMENT

This document is disseminated in the interest of information exchange. The contents of this
report reflect the views of the authors who are responsible for the facts and accuracy of the data
presented herein. The contents do not necessarily reflect the official views or policies of the State
of California or the Federal Highway Administration. This publication does not constitute a
standard, specification or regulation. This report does not constitute an endorsement by the
Department of any product described herein.

For individuals with sensory disabilities, this document is available in alternate formats. For
information, call [phone], TTY 711, or write to California Department of Transportation,
Division of Research, Innovation and System Information, MS-83, P.O. Box 942873,
Sacramento, CA 94273-0001.
ii
D P C
EVELOP A LAN TO OLLECT
P I
EDESTRIAN NFRASTRUCTURE AND
V D F
OLUME ATA FOR UTURE
I C
NCORPORATION INTO ALTRANS
A S
CCIDENT URVEILLANCE AND
A S D
NALYSIS YSTEM ATABASE

FINAL TECHNICAL REPORT

PREPARED BY THE
UC BERKELEY SAFE TRANSPORTATION RESEARCH AND EDUCATION CENTER
FOR THE
CALIFORNIA DEPARTMENT OF TRANSPORTATION

MAY 31, 2014

YUANYUAN ZHANG
FRANK PROULX
DAVID RAGLAND
ROBERT SCHNEIDER
OFFER GREMBEK
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ACKNOWLEDGEMENTS

The authors would like to thank the California Department of Transportation for their support of
this project. We especially acknowledge the support and guidance of Fred Yazdan, Roya Hassas,
Brian Alconcel, Dario Senor, Lucia Saavedra, Dean Samuelson, Johnny Bhullar, Vladimir
Poroshin, Eric Wong, Hau Doan, Bruce De Terra, Tracy Frost, Darold Heikens, Chris Ratekin,
Emilly Mraovich, Debbie Silva, and Mitchell Prevost from Caltrans Head Quarter. Thanks to
Mai Lieu and Mike Pickford for testing the data collection process in District 4 and 11. We also
appreciate the support and corporation of Ronald Au-Yeung, Beth Thomas, Ramiel Gutierrez,
from District 4, and Chris Schmidt, from District 11. Nicole Foletta, Meghan Weir, and Meghan
Mitman have all made valuable contributions to this work. The assistance and advice of Jill
Cooper, Swati Pande, Grace Felschundneff, and Tony Dang are also greatly appreciated. This
work couldn’t have been possible without the dedication and motivation of Yizhe Liu, Brandon
Lee, Noor Al-samarrai, Sana Iqbal Ahmed, and Lilia Houshmand who conducted the data
collection efforts.

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TABLE OF CONTENTS
EXECUTIVE SUMMARY 1
1 INTRODUCTION 2
2 INSTITUTIONAL PROCEDURES AND REQUIREMENTS FOR DATABASE
UPDATING 4
2.1 BACKGROUND 4
2.2 ORIGINS OF TASAS-TSN 4
2.3 DATABASE STRUCTURE 4
2.4 DATABASE UPDATE/MAINTENANCE PROCEDURES 6
2.5 LEGAL CONSIDERATIONS 7
2.6 CONCLUSIONS 7
3 BACKGROUND RESEARCH ON PEDESTRIAN INFRASTRUCTURE
INVENTORIES AND VOLUME MODELING 9
3.1 PEDESTRIAN INFRASTRUCTURE INVENTORIES 9
3.2 DATA COLLECTION PROCEDURES 13
3.3 POTENTIAL ITEMS TO INCLUDE IN PEDESTRIAN DATABASE 14
3.4 CONCLUSIONS 25
4 DATABASE STRUCTURE AND DESIGN 27
4.1 DECOMPOSITION OF A TYPICAL ROAD SEGMENT 27
4.2 COMPONENT DEFINITIONS AND CONNECTIONS 28
4.3 DATABASE STRUCTURE 31
5 DATA COLLECTION MANUAL 34
5.1 FACILITY DATA COLLECTION 35
5.2 VOLUME DATA COLLECTION 57
6 DATA COLLECTION PILOT 60
6.1 COMPUTER DATA COLLECTION 61
6.2 FIELD DATA COLLECTION 66
6.3 VOLUME DATA COLLECTION 67
7 TIME COST FOR DATA COLLECTION 72
7.1 COMPUTER DATA COLLECTION 73
7.2 FIELD DATA COLLECTION 74
7.3 COMPARISONS 75
8 CONCLUSIONS AND RECOMMENDATIONS 77
8.1 CONCLUSIONS 77
8.2 RECOMMENDATIONS 78
APPENDIX 1. Notes from Interview with Eric Fredericks, Caltrans District 3 81
APPENDIX 2. Notes from Interview with Darold Heikens, Caltrans ADA Infrastructure
Program Chief 83
APPENDIX 3. Notes from Interview with Debra Kingsland, New Jersey DOT Bike &
Pedestrian Program Section Chief 84
APPENDIX 4. User Testing and Comments 85
APPENDIX 5. Field Data Collection Packet 101
APPENDIX 6. Time-Estimation Spreadsheet Tool 105
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EXECUTIVE SUMMARY
In this report, a database format is proposed for storing pedestrian and bicycle infrastructure and
volume data collected across the California state highway network. Data collection protocols are
detailed for filling both databases. Additionally, a pilot data collection effort was conducted to
verify that the data can be collected both via computer-based imagery and field-based collection.
In the process of conducting the pilot data collection, the amount of time required was recorded
and used to estimate the total time cost for collecting data across the entire state highway
network.
The database is comprised of two sub-databases, one for infrastructure and one for
volumes. Both of these databases are structured around two “core elements”—nodes and
approaches. These core elements give spatial structure to the database. Nodes are defined as
including typical highway intersections and intersections between highways and cross streets, as
well as mid-block crossings, pedestrian over/underpasses, and periodic locations along highways
where a node has not otherwise been triggered. Approaches are simply defined as connecting
nodes, with one approach for each direction of the highway. “Secondary elements” are then
defined to represent pedestrian and bicycle infrastructure and volumes, which are linked to the
core elements based on spatial location. For example, sidewalks are defined with reference to a
single approach, whereas crosswalks are defined with reference to one node and two approaches.
Using this framework, a number of secondary elements are defined for pedestrian
infrastructure and volumes, including sidewalks, crosswalks, buffers (between the motor vehicle
lane and sidewalk), and bicycle facilities, among others. For each of these elements, a number of
attributes are defined. For example, crosswalk attributes include crossing distance, crosswalk
design, crosswalk color, presence of detectable warning surfaces, presence and type of curb
ramps, and other similar features. Data collection protocols for all of these elements are defined,
including using Google maps/Google Street View and via field observation.
The computer-based data collection procedures were tested on 100 miles of state
highway, and a seven-mile subset of data was collected using field data collection. Of the 100
miles, fifty were chosen from Caltrans District 4, and fifty were chosen from District 11. In
addition to verifying that the data collection process works as intended, the pilot was used to
estimate a time cost for collecting this data across the entire state highway system.
It is uncertain whether the database will eventually be merged into Caltrans’ Traffic
Accident Surveillance and Analysis System (TASAS) - Transportation System Network (TSN),
or whether it will be developed as a separate database with links to TASAS - TSN. Caltrans staff
will need to make a decision about which option fits best within the existing technological
framework.

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1 INTRODUCTION
This report documents California Strategic Highway Safety Plan (SHSP) Action Item 08.09:
“Develop a Plan to Collect Pedestrian Infrastructure and Volume Data for Future Incorporation
into Caltrans Accident Surveillance and Analysis System Database.” For this project, a relational
database was developed to store information on pedestrian and bicycle infrastructure and
volume. This database is designed to be linkable to the existing Caltrans Traffic Accident
Surveillance and Analysis System (TASAS) - Transportation System Network (TSN) database,
which includes information on California’s state highway system including infrastructure (e.g.,
number of lanes, lane widths, etc.), vehicular volumes, and crashes. However, the existing
database does not include any information on pedestrian- and bicyclist-specific infrastructure,
such as the presence of sidewalks or crosswalks, crossing distances, facility widths, etc.
In addition to designing the database, a data collection process to populate the database
was developed and pilot tested across a subset of the state highway system. The data collection
process was developed for both computer-based data collection and field-data collection. The
pilot test encompassed 97.42 miles using the computer data collection method and 7.3 miles
using the field data collection method. In addition to the pilot data collection conducted by the
research team, two Caltrans staff members also tested the data collection protocols on small
stretches of highway to ensure that the process aligns with their expert knowledge of the state
highway system.
The primary goals of this project are to (1) design a flexible database to store pedestrian
and bicycle infrastructure and volume data to be queried in safety analyses, for network
deficiencies, and any other uses; (2) to determine an efficient method of collecting data that can
be scaled for use across the entire state highway system; (3) to pilot test the data collection
process and ensure that all data can be feasibly collected and stored within the database
framework; and (4) to estimate the total time-cost of collecting this data across the entire state
highway system.

Key Components
The report is divided into eight chapters that describe the overall project and findings.
Chapter 1 includes an introduction that elaborates on the purpose and background of the
project.
Chapter 2 details the institutional aspects of the existing TASAS-TSN database,
including the origins of the database, maintenance procedures, and potential concerns about
implementing new variables. The material presented in this chapter is based on a series of
telephone interviews with various Caltrans staff.
Chapter 3 presents a review of similar pedestrian and bicycle infrastructure inventories
carried out in various cities and states. Many cities and a few states have conducted sidewalk
inventories with varying levels of data detail collected. For example, some cities simply note the
presence of sidewalks, whereas others use wheelchair-mounted sensors to collect detailed
information on sidewalk quality conditions. Data collection procedures have included walking
field inventories, review of state highway video logs, and review of still imagery. Chapter 3 also
includes a review of literature on direct demand modeling for pedestrians based on transportation
network and land use characteristics. This literature aims to estimate pedestrian volumes
throughout the network, which is one potential use of the volume database component of this
project.
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Chapter 4 describes the database developed during this project to store pedestrian and
bicycle infrastructure and volume data. The structure used is based on two core elements, nodes
and approaches, which provide the spatial structure for the highway network. Nodes correspond
to intersections, midblock crosswalks, and points every 1-mile along remote highways (i.e.,
whenever nodes do not occur for any other reason). Approaches refer to the connections between
nodes. Approaches are defined by the direction of motor vehicle traffic, meaning that between
two intersections (two nodes) on a bidirectional road, there are two approaches. Secondary
elements such as sidewalks, crosswalks, buffer zones, and bicycle facilities are then each related
by a unique ID to the approaches and nodes. Separate tables are used for each element type (e.g.,
approaches, nodes, sidewalks, crosswalks, buffers).
Chapter 5 includes the Data Collection Manual, a document describing all of the data
elements to be collected for this database in detail. Directions are given for taking different
measurements and for classifying categorical information, such as crosswalk types.
Chapter 6 describes the pilot data collection process and provides instructions for
collecting data in the field. The pilot was conducted with the goals of refining the data collection
process and database format, estimating the total time required to collect data across the entire
state highway network, and checking the feasibility of collecting infrastructural data using
remote imagery. The data collection pilot was conducted in Caltrans Districts 4 and 11 with
support from local staff, and included user testing of the data collection process on a short set of
highway segments by two Caltrans staff members. This user testing served as a peer review to
ensure that professionals not immediately involved with developing the database would be able
to follow the data collection procedures.
Based on the results of the data collection pilot, Chapter 7 provides estimates of the time
required for collection of pedestrian and bicycle infrastructural data across the entire California
state highway network using various data collection processes (computer-based, field-based, and
a hybrid approach). Cost estimates are not provided for populating the volume database. Volume
data is proposed for collection as part of regular traffic safety investigations and other field visits,
as the cost of installing a Miovision camera is very low. The volume data should be collected as
frequently as is feasible.
Finally, Chapter 8 presents conclusions and recommendations for implementation of the
data collection process documented herein. Areas for future discussion include software for use
in implementing the database, whether a GIS-based approach should be considered, connections
to the existing TASAS-TSN system, and plans and a timeline for conducting the complete
pedestrian and bicycle infrastructure inventory.

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2 INSTITUTIONAL PROCEDURES AND REQUIREMENTS
FOR DATABASE UPDATING
2.1 BACKGROUND
This report summarizes the existing data contents and database management practices related to
the TASAS-TSN database. Based on information gathered for this report from Caltrans, it may
be more practical for pedestrian-related data to first be collected and stored in a database that is
parallel to but separate from the existing TASAS-TSN database. These data could eventually be
integrated into the existing system or a future system that incorporates a full set of multimodal
data on the State Highway System, or kept as a standalone system alongside TASAS-TSN.
Background research for this report was conducted through meetings with Caltrans
Transportation Systems Information Staff in fall 2011, a project kick-off meeting in spring 2012,
a review of the current Caltrans Traffic Manual (http://www.dot.ca.gov/hq/traffops/engineering/
control-devices/trafficmanual-current.htm), and telephone interviews with other Caltrans
headquarters and district staff in fall 2012. Notes from these meetings are attached to this
document as appendices.
2.2 ORIGINS OF TASAS-TSN
To the best of our knowledge, the original TASAS database was developed in the 1960s. The
original data fields included automobile volumes and basic automobile infrastructure
information, such as the number of lanes on the roadway, roadway configuration, and median
and shoulder characteristics. All data fields in the current TASAS-TSN database were conveyed
from the Legacy System, an earlier version of the TASAS database. New data fields have not
been added since the database was first created.
2.3 DATABASE STRUCTURE
The TASAS database is currently stored as an Oracle 10g database. The official database is
housed on servers at Caltrans headquarters in Sacramento. TASAS is a component of the larger
Transportation System Network (TSN) database structure, which includes a number of modules
with separate data themes, as shown in Table 1.

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Table 1. Summary of Transportation System Network (TSN) Component Databases
Traffic
Investigation
Traffic Accident Surveillance and
Traffic Census Reporting and
Analysis System (TASAS)
Tracking
System (TIRTS)
Highway
Accident
Inventory
Database
Database
Description Database of traffic Database of all Traffic count data is Documents and
collisions infrastructures on collected and reports on
occurring on the State Highway disseminated by Traffic
State Highway System. Traffic Data Investigations
System. Branch. statewide.
Contact Eric Wong, Debbie Eric Wong, Hau Nick Compin Dean
Person Silva Doan Samuelson
Data California Highway Caltrans HQ and Traffic sensors on Safety
Source Patrol Districts State highways Investigation
Engineers
Who Enters Caltrans HQ Caltrans HQ Caltrans HQ Caltrans HQ
Data?
Data Traffic manual, Traffic manual, 2011 Traffic Traffic Safety
Manual Ch. 3, Ch. 3 Volumes on the Investigator
Accident and Accident and California State Training
Roadway Records Roadway Highway System
Records
Public None None Completely None
Access accessible to public
http://traffic-
counts.dot.ca.gov/
Reports TSAR, Table A, AXR330, Traffic volumes
Generated Table B, Table C, AXRO85, report, truck traffic
Wet Table C AXR085 report, volumes
report and peak
hour volume data
report, monthly
VMT report, county
VMT reports

As noted in the table above, TASAS is comprised of two separate modules. One of these
includes data on crashes within the State Highway network, and the other contains information
regarding infrastructure (known as the “Highway Database,” or “HDB”). Further, a third module
within TSN (Traffic Census) includes traffic volume data along State Highways and on cross
streets at intersections with the State Highway System. Traffic volume data from the Traffic
Census are also integrated into the Highway Inventory Database.

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